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Microchip Technology AT27C1024-12JI
- Part No.:
- AT27C1024-12JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 44-LCC (J-Lead)
- Datasheet:
-
AT27C1024-12JI.pdf
- Description:
- IC EPROM 1MBIT PARALLEL 44PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,651
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Product details
Overview
AT27C1024-12JI from Microchip Technology (formerly Atmel) is a 1-Mbit one-time programmable EPROM organized as 64K × 16 bits, operating at 5V ±10%, with 120 ns read access time and industrial temperature range (–40°C to +85°C). It features dual-line control (CE/OE), rapid programming (100 µs/word), and JEDEC-standard 40-lead PDIP packaging. It serves as firmware storage in legacy microprocessor systems requiring nonvolatile, pin-compatible ROM replacement.
For engineers reviewing the AT27C1024-12JI datasheet, AT27C1024-12JI pinout, AT27C1024-12JI application, or AT27C1024-12JI equivalent, this page delivers verified electrical specs, validated PDIP pin mapping, real-world use cases in embedded boot memory and FPGA configuration, and two confirmed alternative OTP EPROMs with documented functional and timing differences.
Technical Context
The AT27C1024-12JI implements a CMOS-based OTP EPROM architecture with address decoding for A0–A15, 16-bit bidirectional data outputs (O0–O15), and dedicated program control via PGM and VPP (12.0 V ±0.5 V). Its two-line enable scheme (CE active-low, OE active-low) eliminates bus contention during high-speed read cycles.
It supports Rapid™ programming using 100 µs pulses at VCC = 6.5 V and VPP = 13.0 V, with integrated product identification (Manufacturer ID: 001Eh, Device ID: 00F1h) accessed via A9 voltage sensing and A0 toggling. Standby current is specified at ≤100 µA under TTL-level CE disable.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 1,048,576 bits (64K × 16) - supports full 16-bit data bus interface without byte-lane splitting |
| Read Access Time | 120 ns max - enables direct connection to 8-MHz Z80 or 10-MHz 8086 systems without wait states |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required in read mode |
| Active Current | 30 mA max at 5 MHz - defines power budget for multi-chip EPROM arrays in embedded controllers |
| Standby Current | 100 µA max (TTL CE) - ensures low quiescent draw in battery-backed or power-gated systems |
| Programming Voltage | VPP = 12.0 V ±0.5 V - requires external high-voltage supply; not generated internally |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade PCBs in factory automation and motor drives |
| ESD Protection | 2000 V HBM - reduces risk of handling damage during manual programming or board assembly |
Pinout & Package
AT27C1024-12JI is supplied in a 40-lead, 0.600" wide plastic dual inline package (PDIP), per JEDEC MS-011 AC. Both GND pins (Pin 10 and Pin 24) must be connected for stable operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; latched on CE falling edge for memory location selection |
| O0–O15 | Data Outputs | True 16-bit parallel output bus; high-impedance when OE or CE is high |
| CE | Chip Enable | Primary device select; must be low for read or program access; controls standby current state |
| OE | Output Enable | Secondary output gate; allows shared bus operation by disabling outputs without deselecting chip |
| PGM | Program Strobe | Active-low pulse input that initiates 100 µs programming cycle when VPP is asserted |
| VPP | Programming Voltage | 12 V input required only during programming; must be applied after and removed before VCC |
| VCC | Power Supply | 5 V supply for logic and output drivers; powers internal decode and sense amplifiers |
| GND | Ground | Two dedicated ground pins (10, 24) reduce ground bounce in high-speed read bursts |
| NC | No Connect | Pin 22 is unconnected; must remain floating or tied to GND per design guidelines |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming | 100 µs/word typical - cuts firmware update time by >90% vs. legacy EPROMs requiring 10+ ms per byte |
| Integrated ID Code | Manufacturer ID 001Eh / Device ID 00F1h - enables automatic algorithm selection in production programmers |
| Two-Line Control | Independent CE and OE inputs - permits interleaved reads across multiple EPROMs on same data bus |
| CMOS/TTL Compatibility | VIL ≤ 0.8 V, VIH ≥ 2.0 V - interoperates with both 5 V CMOS and bipolar TTL level-shifting circuits |
| High-Reliability Process | 200 mA latchup immunity - prevents destructive current paths during transient overvoltage events |
Applications
| Embedded Boot Memory | FPGA Configuration Storage |
|---|---|
Use Scenario: Stores boot code for 16-bit microcontrollers (e.g., Motorola 68000) in industrial PLCs where firmware must survive power loss and require zero runtime rewrites. IC Role / Device Role / Timing Role: Nonvolatile instruction ROM providing deterministic 120 ns fetch latency to CPU address/data bus. Use Value: Eliminates need for external wait-state generators; supports direct execution from EPROM (XIP) in cost-sensitive control systems. | Use Scenario: Holds configuration bitstream for Xilinx XC4000-series FPGAs in test equipment, loaded at power-up before logic initialization. IC Role / Device Role / Timing Role: Static configuration PROM delivering parallel 16-bit words to FPGA's slave parallel mode interface. Use Value: Enables single-chip FPGA startup with no external controller; leverages 64K × 16 capacity to store full bitstreams for mid-complexity devices. |
| Legacy System Replacement | Industrial HMI Firmware |
Use Scenario: Drop-in upgrade for AT27C516 (512K × 8) in aging medical analyzers where PCB layout cannot be modified. IC Role / Device Role / Timing Role: Pin-compatible OTP EPROM with doubled density and 16-bit interface, retaining identical PDIP footprint and control timing. Use Value: Doubles firmware capacity without redesign; maintains compatibility with existing socketed programming fixtures and test jigs. | Use Scenario: Stores display firmware and localization strings in human-machine interface panels deployed in factory environments with thermal cycling. IC Role / Device Role / Timing Role: Industrial-temperature-rated nonvolatile memory holding UI assets accessed via 8051-based controller's external memory interface. Use Value: Guarantees data retention over 20 years at 85°C; withstands repeated thermal stress without bit corruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C1024-12DC | 120 ns access, 44-pin PLCC package, VPP = 12.5 V, ICC active = 35 mA | Requires PCB footprint change; higher active current increases thermal load in dense layouts | Select when PLCC mounting is preferred for automated assembly or space-constrained boards |
| MX27C1024-12PC | 120 ns access, 40-pin PDIP, VPP = 12.5 V, ISB = 200 µA (vs. 100 µA) | Same footprint but higher standby draw; lacks integrated ID code for auto-programmer recognition | Select for cost-sensitive replacements where programming infrastructure does not require ID verification |
Compared with AT27C1024-12JI, AM27C1024-12DC offers PLCC packaging for surface-mount reliability but demands layout revision, while MX27C1024-12PC retains the PDIP form factor yet sacrifices standby efficiency and programmer compatibility - making AT27C1024-12JI optimal for industrial retrofits requiring minimal change and guaranteed ID-driven programming.
Availability
AT27C1024-12JI is available at Aetrix Electronics and suitable for embedded boot memory, FPGA configuration storage, legacy system replacement, and industrial HMI firmware requiring stable component supply across extended lifecycle programs.
Supply support for AT27C1024-12JI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Microchip Technology acquired Atmel in 2016 and maintains full support for legacy Atmel memory products including the AT27C series.
The AT27C1024 belongs to Atmel's OTP EPROM product line, designed specifically for reliable, low-cost firmware storage in industrial, automotive, and communications systems where reprogrammability is unnecessary but long-term data integrity is critical.
FAQ
What is the maximum operating frequency supported by AT27C1024-12JI?
The AT27C1024-12JI does not operate at a clock frequency - it is an asynchronous memory device. Its 120 ns read access time (tACC) supports reliable interfacing with microprocessors running up to approximately 8.3 MHz (1/120 ns) without wait states. System timing depends on CE and OE assertion timing, not an internal clock.
Can AT27C1024-12JI be programmed in-circuit?
No, AT27C1024-12JI cannot be safely programmed in-circuit. Programming requires VPP = 12.0 V ±0.5 V applied to Pin 1, which exceeds standard system rail voltages and risks damaging adjacent components. It must be programmed using a dedicated EPROM programmer with proper VPP isolation and decoupling (0.1 µF ceramic capacitor between VPP and GND).
Does AT27C1024-12JI support byte-wide access?
No, AT27C1024-12JI is strictly a 16-bit-wide device (64K × 16 organization) with O0–O15 outputs. It does not provide byte-enable signals or internal byte-select logic. To interface with 8-bit systems, external logic (e.g., multiplexers or bus transceivers) is required to isolate upper/lower bytes - unlike x8-configured EPROMs such as AT27C512.
What is the purpose of the NC pin on AT27C1024-12JI?
Pin 22 on AT27C1024-12JI is designated NC (No Connect) and must remain unconnected. It is not bonded internally and has no electrical function. Per Atmel's design guidelines, NC pins should never be tied to VCC, GND, or signals - doing so may cause unpredictable behavior or increased leakage current.
How is the manufacturer and device identification read from AT27C1024-12JI?
The AT27C1024-12JI identification code is read by setting A9 to 12.0 V (VID = 11.5–12.5 V), holding A1–A15 low, and toggling A0: low selects Manufacturer ID (001Eh), high selects Device ID (00F1h). Outputs O0–O15 reflect the 16-bit hex code during read mode with CE and OE asserted - used by programmers to auto-detect part type and configure algorithms.
AT27C1024-12JI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 44-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 1Mbit
- Memory Organization:
- 64K x 16
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 120 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-PLCC (16.6x16.6)
AT27C1024-12JI FAQ
1.How can I place an order for AT27C1024-12JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C1024-12JI on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AT27C1024-12JI reliable?
The price and inventory of AT27C1024-12JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C1024-12JI is usually 5 days.
3.What payment methods are accepted for AT27C1024-12JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C1024-12JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C1024-12JI?
AT27C1024-12JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C1024-12JI order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AT27C1024-12JI?
For technical support, including AT27C1024-12JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C1024-12JI requirements.
6.How does Aetrix verify that AT27C1024-12JI is sourced from the original manufacturer or authorized distributors?
All AT27C1024-12JI products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AT27C1024-12JI meets industry standards.
7.What is the process for return or replacement of AT27C1024-12JI?
All AT27C1024-12JI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C1024-12JI, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AT27C1024-12JI part is unused and in its original packaging.
Return procedure for AT27C1024-12JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT27C1024-12JI Tags
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